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Old 01-14-2019, 11:59 AM   #1
prodjay10
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sbc bent push rod

Would a bent pushrod cause more damage to the engine?

At least one bent push rod. A couple of rocker studs have loose or damaged thread.

I'm trying to decide whether I should fix or rebuild.
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Old 01-14-2019, 12:01 PM   #2
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Re: sbc bent push rod

Sometimes yes...sometimes no.....I'd want to know what that piston looked like...gaskets are cheap
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Old 01-14-2019, 12:49 PM   #3
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Re: sbc bent push rod

I would think it depends on how bad it was bent. I just replaced all my valve seals and discovered 2 bent pushrods on the odd side of my engine. They were just slightly bent, you had to roll them on a hard flat surface to detect the bend. I took the head off and no issues with anything else. Probably were that way for a long time. I replaced them anyway. Good Luck
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Old 01-14-2019, 12:53 PM   #4
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Re: sbc bent push rod

You are correct.

I do have one other issue that I dont know why i forgot to mention. I pulled the spark plugs to replace them and there is oil on the last 2. 7 and 8 I beleive.

The truck had been sitting for years so it may be stem seals? How would i check?
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Old 01-14-2019, 12:54 PM   #5
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Re: sbc bent push rod

The one push rod was also only slightly bent.
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Old 01-14-2019, 05:42 PM   #6
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Re: sbc bent push rod

If the valve seals are leaking change em...no really good way to look at em without pulling them..
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Old 01-14-2019, 06:35 PM   #7
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Re: sbc bent push rod

If the engine hasn't run in years I would pull the heads and get an idea of what it looks like in the cylinders before trying to start it.
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Old 01-14-2019, 06:48 PM   #8
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Re: sbc bent push rod

My last '69 GMC (350 ci) had it's timing chain slip some teeth and all of the exhaust (or intake, I can't remember) push-rods got bent because it was an "interference" engine. I had to finish a big project so I just replaced the timing chain and pounded the push rods as true as I could with a hammer. I ran that truck for years with no problem
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Old 01-15-2019, 03:13 AM   #9
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Re: sbc bent push rod

Thanks for the help. I will be pulling the heads to get a better look.
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Old 01-15-2019, 07:09 PM   #10
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Re: sbc bent push rod

Quote:
Originally Posted by WorkinLonghorn View Post
My last '69 GMC (350 ci) had it's timing chain slip some teeth and all of the exhaust (or intake, I can't remember) push-rods got bent because it was an "interference" engine. I had to finish a big project so I just replaced the timing chain and pounded the push rods as true as I could with a hammer. I ran that truck for years with no problem
I did the same type of activity but I sold my truck to a dude from Texas. As far as I know the dude is still driving that truck around in Texas and that was 4 years ago. Something about fixing what you can and it works without spending a dime and selling to make out great on it.
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Old 01-17-2019, 03:08 AM   #11
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Re: sbc bent push rod

Out of curiosity, anyone know how to remove oil from hydraulic lifters? Can i just leave it sitting for a certain amount of time?

I dont want to adjust the valves with the engine running unless I absolutely have to. Oil everywhere and burning on the exhaust manifolds is not fun.
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Old 01-17-2019, 09:59 AM   #12
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Re: sbc bent push rod

Why would you need to remove oil from the lifters?
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Old 01-17-2019, 10:53 AM   #13
prodjay10
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Re: sbc bent push rod

To adjust the valves.

https://youtu.be/5EGlb_VpTAw
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Old 01-17-2019, 12:22 PM   #14
geezer#99
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Re: sbc bent push rod

But you’re not adjusting new lifters so just do it normally.
With one exception.
Wiggle the rocker until all the slack is out of it instead of twisting the pushrod.
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Old 01-17-2019, 01:22 PM   #15
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Re: sbc bent push rod

Quote:
Originally Posted by geezer#99 View Post
But you’re not adjusting new lifters so just do it normally.
With one exception.
Wiggle the rocker until all the slack is out of it instead of twisting the pushrod.
Totally agree. I had bad luck with the twisting method. I don't think I'm that much stronger than average, but it was pretty easy for me to twist the pushrod even as the plunger was compressing into the lifter. Wiggle method is much better to figure out how to detect that initial slack.
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Old 01-19-2019, 11:30 AM   #16
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Re: sbc bent push rod

I would suggest you install your new pushrods & after adjusting the valves do a compression test. If the compression is even all across then no bent valves, if no bent valves then they didn't smack any pistons!
You can also introduce air into the cyl in question thru the spark plug hole without the rockers installed. If no leak from intake or exaust manifolds you're good to go!
Lotta un necessary work to pull heads when a few minutes of CORRECT diagnosis could point you in the right direction.
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